10 sec delay on play wave file in IVR

We notice that in versione 9 using abyss server we have a 10 second delay when 3CX play wave audio files associated to an IVR. File are 44.1 Khz 16 bit mono.
We have no problem with version 8 but after upgrade we notice this issue.
OS is Windows 2008 Server R2 with Desktop Experience enabled.
Any solution ?